Finding the Third Proportional to 142,216 and 213,686

Step by Step Solution

1. Step 1: Write the proportion equation
   142,216 : 213,686 = 213,686 : x
2. Step 2: Convert to fraction form
   142,216/213,686 = 213,686/x
3. Step 3: Cross multiply
   142,216x = 213,686 × 213,686
4. Step 4: Simplify right side
   142,216x = 45,661,706,596
5. Step 5: Solve for x
   x = 45,661,706,596/142,216
6. Step 6: Final answer
   x = 321,072.92